Analytical methods of generating multiple sound zones for open and baffled circular loudspeaker arrays

This paper proposes analytical methods for generating acoustically bright and dark zones on the horizontal plane using circular loudspeaker arrays without and with a cylindrical rigid baffle. Both sound fields on the horizontal plane produced by continuous circular monopole source distributions without and with a rigid baffle are analytically calculated using 2.5D sound field representation derived from the 3D cylindrical harmonics expansion. Efficient spatial filters in the spatial Fourier series domain are analytically derived by modeling sound pressures at the control circle as a rectangular window that corresponds to bright and dark zones. The computer simulation results show that the proposed methods can generate bright and dark zones near the loudspeakers more accurately than conventional least squares and beamforming methods.